1. Field of the Invention
The present invention is concerned with novel compositions which are reversibly liquid at lower temperatures or solid at higher temperatures and process for preparing the same.
2. Description of the Prior Art
There are known almost none of substances, as they are, in solution or in composition, that are reversibly liquid or in solution at lower temperatures and solvent-insoluble solid at higher temperatures. In the art are known a number of high-molecular substances called thermosetting resin, for most of which conversion from the non-cross-linked state to the cross-linked state is effected by heating. The change is irreversible and the cross-linked high-molecular substance will no longer be reversed to the original non-cross-linked state even with the heating removed or cooling. The same applies to the solution of a thermosetting resin; when a thermosetting resin is dissolved in a solvent such as water followed by heating, in the presence of a curing agent in some cases, there occurs a cross-linking reaction thereby forming cross-linked macromolecules, being swelled in most cases. They will no longer be reversed to the original solution state.
It would, therefore, permit a wide variety of uses in various industrial fields to provide a composition which is reversibly solid at higher temperatures and liquid at lower temperatures.